Catamaran boat construction with center spray shield



J. v. YOST 3,401,663

CATAMARAN BOAT CONSTRUCTION WITH CENTER SPRAY SHIELD 2 Sheets-Sheet 1 Sept. 17, 1968 Filed Dec. 27, 1966 John 1/. Yost INVENTOR.

wflwayfim Sept. 17, 1968 J. v. YOST 3,401,663

CATAMARAN BOAT CONSTRUCTION WITH CENTER SPRAY SHIELD 2 Sheets-Sheet 2 Filed Dec. 27, 1966 John M Yosr INVENTOR.

United States Patent 3,401,663 CATAMARAN BOAT CONSTRUCTION WITH CENTER SPRAY SHIELD John V. Yost, 2233 Riverside rive, Trenton, Mich. 48183 Continuation-impart of application Ser. No. 519,618, Jan. 10, 1966. This application Dec. 27, 1966, Ser. No. 604,763

15 Claims. (Cl. 114-665) ABSTRACT OF THE DISCLOSURE A boat hull construction of the catamaran type including a pair of generally parallel elongated hull members supported from a somewhat raised center passenger supporting body portion and including a panel-like substantially imperforate spray shield and supplemental planing surface member extending between the hull members, the latter having their rear ends pivotally supported from the rear end of the passenger supporting body for oscilla tion about a horizontal transverse axis and the forward ends of the hull members being mounted for limited vertical swinging movement relative to the forward end of the passenger supporting body and yieldingly urged toward their lowermost positions with respect to the body.

This invention comprises a continuation-in-part application of my copending US. application Ser. No. 519,618, filed Jan. 10, 1966 for Boat Construction, now US. Patent No. 3,326,166, dated June 20, 1967.

The instant invention relates to a catamaran type of hull construction including longitudinally extending and transversely spaced hull members oscillatably supported from a bridging passenger supporting body at their rear ends for oscillation about a horizontal transverse axis and also provided with means interconnecting the front ends of the hull members and the forward end of the passenger supporting body for limited vertical swinging movement of the forward ends of the hull members relative to the body with the former being yieldably urged toward their lowermost positions relative to the body, the improvement of this invention consisting of a flexible and generally panel-like member extending between the hull members below the body and above the lower planing surfaces of the hull members and defining a spray shield and supplemental planing surface.

In addition to the boat construction of the instant invention having as its objects those objects specifically set forth in the above copending application, a further object of the instant invention is to provide a catamaran type of boat hull construction better adapted to be utilized in conjunction with a single outboard motor installation, or at least an outboard motor installation, either single or dual, whose lower unit or units are spaced transversely inwardly of the confronting inner surfaces of the two hull members of the catamaran type boat.

In the past it has been found that whenever one or more outboard motors are disposed'between the rear ends of the hull members of a catamaran type boat the propellers of such outboard motor installations have a tendency to break the surface of a supporting body of water resulting in the rapidly spinning propellers cutting holes in the water in which air is disposed. This is an operational feature which is highly detrimental to outboard motor operation and appreciably reduces the driving thrust which may be developed by an outboard motor and is referred to as cavitation.

Some boat manufacturers have therefore attempted to incorporate into a single hull the advantages of stability afforded by a catamaran type hull and the advantages of 3,401,663 Patented Sept. 17, 1968 ice reduction in cavitation afforded by a conventional hull. To this end some manufacturers have provided more or less conventional planing boat hulls with depending opposite side and longitudinally extending hull portions which function to some degree in the same manner as the twin hull members of a catamaran type hull. By this construction the central portion of the rear end of a boat hull is not completely elevated above the rear ends of the depending opposite side hull members or portions and therefore the hull has a tendency to smooth out the surface of the water immediately forwardly of an outboard motor or motors disposed between the depending opposite side hull portions. However, this construction also presents a rigid center planing surface between the depending opposite side hull portions and therefore some of the desirable handling and riding characteristics of a conventional catamaran type hull are sacrificed.

It is therefore a further object of this invention to provide a flexible water spray and supplemental panel-like planing member to extend between the opposite side hull members of a catamaran type hull, the supplemental panel-like planing member being operable to smooth out the surface of the water immediately forwardly of an outboard motor secured to the central portion of the rear of the hull and yet sufficiently yieldable to maintain a majority of the desirable riding characteristics of a conventional catamaran type hull.

Another object of this invention is to provide a hull of the aforementioned type including a flexible panel-like supplemental planing member and which may be adjusted in fore-and-aft inclination relative to the opposite side hull members of the associated catamaran type hull.

Yet another object of this invention is to provide such an improved flexible and panel-like supplemental planing member for the improved catamaran type hull disclosed in the above-mentioned copending application.

A final object of this invention to be specifically enumerated herein is to provide a hull construction in accordance with the preceding objects which will conform to conventional forms of manufacture, be of simple construction and easy to operate so as to provide a device that will be economically feasible, long lasting and relatively inexpensive in operation.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a perspective vow of the boat construction of the instant invention;

FIGURE 2 is a front elevational view of the boat construction illustrated on somewhat of an enlarged scale;

FIGURE 3 is a somewhat enlarged longitudinal vertical sectional view taken substantially upon the plane indicated by the section line 33 of FIGURE 1;

FIGURE 4 is a fragmentary transverse sectional view taken substantially upon a plane passing through the longitudinal center of the body compartment of a modified form of boat construction constructed in accordance with the present invention; and

FIGURE 5 is a fragmentary end elevational view of the boat construction of FIGURES l-3.

Referring now more specifically to the drawings the numeral 10 generally designates the boat construction of the instant invention which may be seen to include an upper centrally disposed passenger supporting body referred to in general by the reference numeral 12 and a pair of opposite side longitudinally extending hull members generally referred to by the reference numerals 14 and 16.

The body 12 includes opposite side walls 18 and 20, a

bottom wall 22 and a partial top wall 24 as well as a rear upstanding transom 26 which is adapted to have any suitable form of outboard motor mounted thereon centrally intermediate the opposite side walls 18 and 20.

The transom 26 is secured to the rear end of the bottom wall 22 and also interconnects the rear ends of the side walls 18 and 20. Further, the forward ends of the op posite side Walls 18 and 20, the bottom wall 22 and the partial top wall 24 converge together to form a how 28 and the body 12 includes a windshield construction generally referred to by the reference numeral 30 as well as a seat construction generally referred to by the reference numeral 32 for supporting the operator of the boat construction 10 as well as any passengers accompanying the operator.

The hull members 14 and 16 are identical in configuration and are hollow so as to be buoyant. The hull members 14 and 16 include top walls 34 and similar inwardly facing adjacent side walls 36 and 38. The rear ends of the hull members 14 and 16 are pivotally secured to opposite side portions of the rear end of the body 12 by means of suitable hinge assemblies 40 and 42 and the forward end of the body 12 has a pair of opposite side spring and shock absorbing strut assemblies 44 secured thereto by means of suitable pivot fasteners 46, the lower ends of the assemblies 44 being pivotally supported from suitable brackets 48 anchored to the to walls 34 by means of pivot fasteners 50.

The assemblies 44 obviously tie the forward ends of the hull members 14 and 16 to the opposite sides of the body 12 and resist lateral displacement of the hull members 14 and 16 and the body 12 relative to each other. F urther, the assemblies 44 secure the forward ends of the hull members 14 and 16 to the forward end of the body 12 for limited vertical swinging movement of the hull members 14 and 16 relative to the body 12 and yieldably urge the forward ends of the hull members 14 and 16 toward their lowest positions of movement relative to the forward end'of the body 12.

A stiff but flexible panel member generally referred to by the reference numeral 52 is provided and is generally in the shape of an elongated inverted channel mem ber extending longitudinally between the hull members 14 and 16. The channel member 52 includes a pair of depending opposite side legs 54 and 56 which smoothly curve toward each other along their upper marginal edge portions to form an integral bridging bight portion 58. The lower marginal edge portions of the legs 54 and 56 are secured to the side walls 36 and 38 of the hull members 14 and 16 by means of any suitable fasteners 60 and the bight portion 58 includes a longitudinally extending slightly rearwardly tapered stiffening panel 62 which overlies its upper surface and is secured thereto by means of suitable fasteners 64 secured through longitudinally spaced portions of the opposite side marginal portions of the panel 62, the underlying portions of the bight portion 58, and a pair of anchoring strips 66 extending along beneath the portions of the bight portion 58 underlying the opposite side marginal portions of the stiffening panel The rear end of the stiffening panel 62 is supported from the central portion of the rear of the bottom panel 22 of the body 12 by means of longitudinally extendible elongated struts 68 pivotally secured to the stiffening panel 62 at their lower ends and to the bottom wall 22 at their upper ends. In addition, the forward end portion of the stiffening panel 62 has a pair of mounting brackets 70 secured thereto by means of suitable fasteners 72 and a pair of expansion springs 74 are interconnected between the brackets 70 and similar brackets 76 secured to the bottom wall 22 of the body 12.

With reference now more specifically to FIGURE 4 of the drawings, there may be seen a modified form of boat construction generally referred to by the reference numeral 10 and which is substantially identical to the boat construction 10 except that the panel member 52' thereof does not include a stiffening member such as stiffening panel 62 but instead includes a downwardly offset center portion 23 of the bottom wall 22' including a lower bottom wall portion 22" closely overlying and generally paralleling the bight portion 58 of the panel member 52. If it is desired, the forward end portion of the bight portion 58 may be supported from the body 12' by means of expansion springs (not shown) corresponding to expansion springs 74.

In operation, the form of panel member 52 illustrated in FIGURES l-3 and 5 serves as a flexible substantially impervious water shield and supplemental planing surface. It may be seen from FIGURE 3 of the drawings that the panel member 52 is rearwardly and downwardly inclined relative to the lower planing surfaces of the hull members 14 and 16 and that the inclination of the panel member 52 may be adjusted by adjusting the effective length of the elongated members 68. Further, the forward end of the bight portion 58 is held up by the springs 74 against flopping downwardly toward the water on which the boat construction 10 is disposed and therefore will not have any tendency to scoop water up and over the forward end of the panel member 52 during forward movement of the boat construction 10.

Inasmuch as the panel member 52 is somewhat flexible, although backed by the stiffening panel 62, any impact of water striking the panel member 52 will be transferred only partly to the hull members 14 and 16 and therefore the boat construction 10 may ride over choppy water at high speeds with substantially all of the improved handling characteristics of a conventional catamaran type hull but with the panel member 52 smoothing out the surface of the water immediately forwardly of an outboard motor or motors centrally mounted on the transom 26. Thus, although the improved handling characteristics of a catamaran type hull are retained, outboard motors may be readily utilized to propel the boat construction 10 without excessive cavitation.

That form of the invention illustrated in FIGURE 4 of the drawings functions in substantially the same manner although the bottom wall portion 22" is utilized in lieu of a stiffening panel such as stiffening panel 62 so as to maintain at least the central portion of the bight portion 58' in a substantially planar condition even when the hull construction 10' is moving at high speed over choppy water. Because of the generally inverted U-shaped configuration of the panel members 52 and 52', there is little tendency of the central portion of the bight portion 58 to droop downwardly between the upper ends of the leg portions of the panel members 52 and 52'. Further, the panel members 52 and 52' are constructed of relatively stiff material and the stiffening panel 62 utilized on the panel member 52 positively prevents any such drooping of the panel member 52.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. A boat construction including a pair of lower laterally spaced elongated and generally parallel buoyant hull members including lower planing surfaces, an upper body for supporting an operator extending longitudinally of said hull members and bridging the space therebetween, means supporting at least the forward end portions of said hull members from said body for limited up and down movement relative to said body, said construction including flexible surface means extending between said hull members defining a substantial spray shield and supplemental planing surface extending longitudinally of said boat construction with at least a major portion of the length of said shield and supplemental planing surface disposed above said lower planing surfaces of said hull members, and means yieldingly urging the forward end portions of said hull members toward their lowermost limits of travel relative to said body.

2. The combination of claim 1 wherein said surface means includes means operative to vary the elevation of the rear of said surface means relative to said body.

3. The combination of claim 1 wherein said surface means comprises lower surface portions of a flexible panel-like member extending between said hull members.

4. The combination of claim 3 wherein said panel-like member includes elongated stiffening means extending longitudinally thereof, spaced inwardly of the opposite sides of said panel-like member and supported from said body.

5. The combination of claim 4 wherein said elongated stiffening means is dependingly supported from said body.

6. The combination of claim 5 wherein the rear end of said stiffening means is pivotally supported from said body for oscillation about an axis extending transversely of said body and the forward end of said stiffening means is supported from said body for vertical movement relative thereto, and means connected between said body and said stiffening means limiting downward movement of the latter relative to said body.

7. The combination of claim 6 wherein said means connected between said body and said stiffening means includes means yieldingly limiting downward movement of the forward end of said stiffening means relative to said body.

8. A boat construction including a pair of lower laterally spaced apart elongated and generally parallel buoyant hull members including lower planing surfaces, an upper body supported from and extending longitudinally of said hull members and bridging the space therebetween, said construction including flexible surface means spaced below said upper body and extending between and supported at its opposite sides from said hull members defining a spray shield and supplemental planing surface extending longitudinally of said boat construction with at least a major portion of the length of said shield and supplemental planing surface disposed above the planing surfaces of said hull members.

9. The combination of claim 8 wherein said surface means is defined by the lower surface portions of a stiff but somewhat flexible panel secured between said hull members and including portions thereof and are generally horizontally disposed which span at least one-half the distance between said hull members.

10. The combination of claim 1 wherein said spray shield includes a rear end portion spaced between said hull members, elongated upstanding spacing means extending between and pivotally connected, at its upper and lower ends, to the rear end portions of said body and spray shield, respectively, for rotation about horizontal transverse axes.

11. The combination of claim 10 wherein said elongated spacing means comprises elongated longitudinally adjustable screw jack means.

12. The combination of claim 9 wherein said surface means is defined by lower surface portions of a flexible panel secured between said hull members and including a stiffened generally horizontal center section thereof terminating outwardly in smoothly downwardly curving opposite side marginal portions whose lower marginal edge portions are secured to said hull members.

13. The combination of claim 12 including front and rear means carried by said upper body supporting the front and rear ends of said stiffened central section.

14. A boat construction including a pair of laterally spaced apart elongated and generally parallel buoyant hull members including lower planing surfaces, flexible surface means extending between and supported at its opposite sides from said hull members defining a spray shield and supplemental planing surface extending longitudinally of said boat construction with at least a major portion of the length of said shield and planing surface disposed above the planing surfaces of said hull members.

15. The combination of claim 14 wherein said surface means is defined by lower surface portions of a flexible panel secured between said hull members and including a stiffened generally horizontal section thereof terminating outwardly in smoothly downwardly curving opposite side marginal portions whose lower marginal edge portions are secured to said hull members.

References Cited UNITED STATES PATENTS 1,738,979 12/1929 Adelmann 114 61 XR 3,326,166 6/1967 Yost ll4-66.5 3,345,967 10/1967 Sweet 11461 ANDREW H. FARRELL, Primary Examiner. 

